Aluminum Matrix Syntactic Foam Fabricated with Additive Manufacturing

Syntactic foams are lightweight structural composites with hollow reinforcing particles embedded in a soft matrix. These materials have applications in transportation, packaging, and armor due to properties such as relatively high specific stiffness, acoustic dampening, and impact absorption. Aluminum matrices are the most widely studied of metal matrix syntactic foams, but there is little to no research in regards to processing the foams with additive manufacturing. It is theorized that the fast cooling rates and limited kinetic energy input of additive could reduce two issues commonly associated with processing syntactic foams: microsphere flotation in the melt and microsphere fracture during processing. In this study, 4047 aluminum blended with glass particles was deposited on a 4047 Al substrate using an additive process. Characterization of the foams include mechanical testing and microstructural analysis.